David Lammy raised the case of a jailed British-Egyptian pro-democracy activist with officials in Cairo this week, Downing Street said, as it faced criticism from the man’s mother over his ongoing imprisonment.

Laila Soueif, who has been on hunger strike for 117 days in protest over her son Alaa Abd El-Fattah’s treatment in Egypt, has urged Sir Keir Starmer to intervene as “time is running out”.

On Friday, she accused the Prime Minister of not having “deigned to reply” to a letter she sent him last week about her son’s plight.

Mr Abd El-Fattah, 43, has been detained in Egypt since September 29 2019, and in December 2021 was sentenced to five years in prison after being accused of spreading false news.

Asked about the case on Friday, No 10 said his imprisonment had been a “focus” of Mr Lammy’s meetings with the Egyptian government as he visited the country on Thursday.

It added that the Prime Minister had also raised the case with Egyptian President Abdel Fattah El-Sisi.

Asked whether the Prime Minister would meet Ms Souief, a Number 10 spokesman said: “Obviously we will set out prime ministerial meetings in the usual way.”

Asked whether he plans to respond to her letter, the official said: “I don’t have an update on that specific point … in terms of timelines, the Foreign Secretary raised this case a number of times with his counterpart, most recently in Saudi Arabia when he met the foreign minister of Egypt there.”

Asked whether Sir Keir had a message for Ms Soueif on the 117th day of her hunger strike, No 10 said there would be an “update in due course” after she wrote to the Prime Minister.

“In terms of the Foreign Office, our officials remain in regular contact with her and her family to check on her welfare,” the spokesman said.

Foreign Secretary David Lammy with Egyptian foreign minister Badr Abdelatty ahead of a bilateral in Cairo, Egypt (Stefan Rousseau/PA)

Ms Soueif, 68, warned on Friday that her “blood sugar levels are dropping” as low as 2.8mmol/L and “I feel more tired every day”.

“I have always said that ultimately it is the Prime Minister who must talk directly to President Sisi to secure Alaa’s freedom,” she said on Friday.

“There were hopes that Mr Lammy would bring Alaa back with him and reunite him with his son in Brighton, but it is clear this is not happening. I am devastated for my son and my grandson. They deserve to be together.

“But I have always said that ultimately it is the Prime Minister who must talk directly to President Sisi to secure Alaa’s freedom. Mr Starmer has not even deigned to reply to the letter I sent him over a week ago requesting a meeting.

“The Prime Minister must know that time is running out. My blood sugar levels are dropping and I feel more tired every day. He needs to intervene to bring Alaa to his family in the UK before it is too late.”

Sanaa Seif, Mr Abd El-Fattah’s sister, welcomed the Foreign Secretary raising her brother’s case but said the Egyptian foreign affairs minister “functions as a dignified mailbox” and is “not the man keeping my brother hostage”.

“My family needs Keir Starmer to intervene and talk directly to President Sisi to free Alaa,” she said.

“Why is the Prime Minister ignoring our meeting request? Is the Prime Minister waiting until my mum is in hospital to pay attention to us?

“I’m told Alaa is a priority for the British government and I want to believe that but we need Keir Starmer to act now before it’s too late.”